What might this gospel parable be about?

It certainly could address those questions of Jesus or the early Markan community about why some people don't respond to the Gospel and some do.  That makes a lot of sense and, if the reader wants a quick and dirty course on such issues, look at the New Jerome Biblical Commentary's work on the Gospel of Mark by Daniel J. Harrington, SJ (especially, page 605, #25ff).

However, I don't find many folks asking such questions today.  Some, just not many.  It seems to me that many of us ask, "Why do I seem divided when it comes to following Christ?"  I find this parable to answer that question to some extent. 

Imagine that a person's life, your life, for example, could be shown on a map.  Lowlands, mountains, deserts, rivers of life, and such would appear on different parts of the map.  But, let's say we make the map really small and focused.  This map just reveals a part of a field.  There are rocks and paths and soil.  But, how do we know what's in the darn field?  Let the seed be sown and see what happens!

When the seed hits the field, all kinds of things happen: some seed falls on the path to be food for birds, some on rocky ground, some among the thorns, and some on the good soil.  Voila, now we know more of the field's geography!  Now we know where some of those nasty things are.

Before taking the next logical step, however, and saying that, well, let's just sow the seed only in the good soil...duh!...let's look at it another way, a way that has less to do with North American pragmatism.

In his wonderfully enlightening book, The Human Condition, Fr. Thomas Keating portrays the spiritual journey of contemplation as one that not only has to encounter the false self - those aspects of one's life that go against the Gospel - but as one whose practice draws forth the false self so that it can be healed by the mercy of God.  In other words, the practice of contemplation attracts the very path & birds, rocks, and thorns that we would be rid of!

My quick application to the parable is this: it is the sowing of the seed that not only reveals, but even draws forth path & birds, rocks, and thorns!  Thus, the presence of the Word draws out those many resistances (symbolized by path, rocks, and thorns) to encounter the love and mercy of God.

I don't think we are called to be "nice people."  I'm not sure we're even called to "clean up our little fields" to make them more presentable to God and others.  I'm wondering whether we're not invited by this parable first, to be amazed at what God can do with whatever patch of good soil the divine mercy has given us.  Second, I'm wondering whether we're not invited to be amazed at God's mercy that loves our precious little field even before we can do a darn thing about it.